1. B. K. Vul'f, Heat Treatment of Titanium Alloys [in Russian], Metallurgiya, Moscow (1969).
2. S. S. Kiparisov and Yu. V. Levinskii, Nitriding of Refractory Metals [in Russian], Metallurgiya, Moscow (1972).
3. A. T. Tumanov (ed.), Use of Titanium in the National Economy [in Russian], Tekhnika, Kiev (1975), p. 42.
4. E. N. Novikova, "Nitriding of titanium alloys," in: Titanium and Its Alloys [in Russian], No. 3, Izd. Akad. Nauk SSSR (1960), p. 35.